Source code for swh.counters.history

# Copyright (C) 2021  The Software Heritage developers
# See the AUTHORS file at the top-level directory of this distribution
# License: GNU General Public License version 3, or any later version
# See top-level LICENSE file for more information
import json
import logging
import os
import time
from typing import Dict, List, Optional

import requests

logger = logging.getLogger(__name__)

[docs]class History: """Manage the historical data of the counters""" def __init__( self, prometheus_host: str, prometheus_port: int, live_data_start: int, cache_base_directory: str, interval: str = "12h", prometheus_collection: str = "swh_archive_object_total", query_range_uri="/api/v1/query_range", labels: Dict[str, str] = {}, ): self.prometheus_host = prometheus_host self.prometheus_port = prometheus_port self.cache_base_directory = cache_base_directory self.live_data_start = live_data_start self.interval = interval self.prometheus_collection = prometheus_collection self.query_range_uri = query_range_uri self.labels = labels def _validate_filename(self, filename: str): if "/" in str(filename): raise ValueError("filename must not contain path information") def _compute_url(self, object: str, end: int,) -> str: """Compute the api url to request data from, specific to a label. Args: object: object_type/label data (ex: content, revision, ...) end: retrieve the data until this date (timestamp) Returns: The api url to fetch the label's data """ labels = self.labels.copy() labels["object_type"] = object formated_labels = ",".join([f'{k}="{v}"' for k, v in labels.items()]) url = ( f"http://{self.prometheus_host}:{self.prometheus_port}/" f"{self.query_range_uri}?query=sum({self.prometheus_collection}" f"{{{formated_labels}}})&start={self.live_data_start}&end={end}&" f"step={self.interval}" ) return url
[docs] def get_history(self, cache_file: str) -> Dict: self._validate_filename(cache_file) path = f"{self.cache_base_directory}/{cache_file}" with open(path, "r") as f: return json.load(f)
def _adapt_format(self, item: List) -> List: """Javascript expects timestamps to be in milliseconds and counter values as floats Args item: List of 2 elements, timestamp and counter Return: Normalized tuple (timestamp in js expected time, counter as float) """ timestamp = int(item[0]) counter_value = item[1] return [timestamp * 1000, float(counter_value)] def _get_timestamp_history(self, object: str,) -> List: """Return the live values of an object""" result = [] now = int(time.time()) url = self._compute_url(object=object, end=now,) response = requests.get(url) if response.ok: data = response.json() # data answer format: # {"status":"success","data":{"result":[{"values":[[1544586427,"5375557897"]... # noqa # Prometheus-provided data has to be adapted to js expectations result = [ self._adapt_format(i) for i in data["data"]["result"][0]["values"] ] return result
[docs] def refresh_history( self, cache_file: str, objects: List[str], static_file: Optional[str] = None, ): self._validate_filename(cache_file) if static_file is not None: static_data = self.get_history(static_file) else: static_data = {} # for live content, we retrieve existing data and merges with the new one live_data = {} for object in objects: prometheus_data = self._get_timestamp_history(object=object) live_data[object] = static_data.get(object, []) + prometheus_data target_file = f"{self.cache_base_directory}/{cache_file}" tmp_file = f"{target_file}.tmp" with open(tmp_file, "w") as f: f.write(json.dumps(live_data)) os.rename(tmp_file, target_file)